Flat Mushroom. In the Light Encounters handbook, players say that Mushroom Card is a reference to one of Kasumigaya's graduating twin ancestors, the Flat Mushroom. There are two types of Mushroom Card, a child type, which is usually this type, are held in the arms of the Mushroom, so do not need to wear shoes, and an adult type, which relies on the Mushroom to lend energy to Kaka to maintain the adult type.